• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1149-1152
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• 2005

Recently, tunnel structure is being widely used in railway or roadway construction projects because earthwork causes large cutting and damages in environmental factors. However, there are many changes of design by different items comparing with design phase in tunnel structure by uncertain drawings. This study develops a standard process for the change of design to reduce change orders in construction phase.

• 대한전기학회논문지
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• 제38권6호
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• pp.441-450
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• 1989

A control technique for current-fed filters is proposed which not only eliminates the harmonic current, but also controls the reactive power at the ac sides of PWM inverter-induction motor drive system. Injecting the proposed PWM current enables the harmonic components of orders not greater than the number of pulses per half-cycle to be removed completely. Also it enables the input fundamental power factor to become unity and hence total input power factor can be improved greatly. Digital simulation is performed to investigate the theoretical output characteristics of the current-fed filters by the proposed control technique.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권7호
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• pp.462-467
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• 2005

In this paper, we analyzed normal gait acceleration signal by time series analysis methods. Accelerations were measured during walking using a biaxial accelerometer. Acceleration data were acquired from normal subjects(23 men and one woman) walking on a level corridor of 20m in length with three different walking speeds. Acceleration signals were measured at a sampling frequency of 60Hz from a biaxial accelerometer mounted between L3 and L4 intervertebral area. Each step signal was analyzed using Box-Jenkins method. Most of the differenced normal step signals were modeled to AR(3) and the model didn't show difference for model's orders and coefficients with walking speed. But, tile model showed difference with acceleration signal direction - vertical and lateral. The above results suggested the proposed model could be applied to unit analysis.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3012-3017
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• 2021

The spatial distribution and the energy spectrum of the neutron yield were investigated with the neutron activation analysis and MCNP simulation was carried out to verify the analysis results and to extend the results to a 3D mapping of the neutron yield distribution in the KSTAR. High purity Ni specimen was selected in the neutron activation analysis. Total neutron yields turned out to be 3.76 × 10¹² n/s - 7.56 × 10¹² n/s at the outer vessel of the KSTAR, two orders of magnitude lower than those at the inner vessel of the KSTAR, which demonstrates the attenuation of neutron yield while passing through the different structural materials of the reactor. Based on the fully expanded 3D simulation results, 2D cross-sectional distributions of the neutron yield on XY and ZX planes of KSTAR were examined. The results reveal that the neutron yield has its maximum concentration near the center of blanket and decreases with increasing proximity to the vacuum vessel wall.

• 헤리티지:역사와 과학
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• 제42권1호
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• pp.72-87
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• 2009

우리나라 천연기념물로 지정된 10개 천연보호구역 가운데 홍도, 설악산, 한라산, 대암산 대우산, 향로봉 건봉산 및 독도천연보호구역에 대해 조사 및 문헌을 토대로 서식 곤충 다양성을 분석한 결과, 한라산천연보호구역이 22목 1,867종으로 종다양성이 가장 높은 것으로 나타났다. 다음은 설악산천연보호구역으로 19목 1,604종, 향로봉 건봉산천연보호구역이 18목 704종, 홍도천연보호구역 19목 474종, 대암산 대우산천연보호구역이 16목 468종, 독도천연보호구역 11목 114종 순으로 각각 나타났다. 천연보호구역에서 출현한 곤충목들 가운데 나비목은 홍도, 설악산, 한라선, 향로봉 건봉산 등 4개 천연보호구역에서 우점분류군으로 나타났고 딱정벌레목은 아우점분류군으로 확인되었다. 한편 대암산 대우산천연보호구역과 독도천연보호구역에서는 반대로 딱정벌레목이 우점분류군, 나비목이 아우점부류군으로 출현하였다. 나머지 주요 목들의 출현 양상을 각 지역별로 비교하면 하루살이목은 25종이 출현한 설악산천연보호구역, 잠자리목은 28종이 출현한 한라산천연보호구역, 집게벌레목은 9종이 출현한 설악산천연보호구역, 메뚜기목은 51종이 출현한 한라산천연보호구역, 노린재목은 175종이 출현한 한라산천연보호구역, 매미목은 126종이 출현한 설악산천연보호구역, 벌목은 183종이 출현한 한라산천연보호구역, 파리목은 206종이 출현한 한라산천연보호구역에서 각각 가장 높은 종다양성을 보여주었다. 이들 가운데 천연보호구역별 학술조사 규모 및 횟수의 차이는 있으나 향로봉 건봉산천연보호구역, 대암산 대우산천연보호구역 및 독도천연보호구역에서 곤충상이 빈약하게 나타난 것은 다른 원인도 있지만 다양한 종합조사 부족에 따른 결과가 가장 큰 것으로 사료된다. 더구나 성산일출봉천연보호구역, 문섬 범섬천연보호구역, 차귀도천연보호구역, 마라도 천연보호구역들은 지정당시 조사는 물론, 지정 후 지금까지 육상곤충에 대한 종합학술조사가 수행된 바가 없다. 따라서 이들 지역에 대한 곤충상 학술조사가 시급히 필요하며, 이들 조사결과를 바탕으로 지역별 특성을 고려한 관리 및 보전 기본계획을 수립해야 할 것으로 사료된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.155-160
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• 1996

The vibration analysis of the automobiles has been a good subject for the engineers seeking solutions for more comfortable life. In the area of industrial vehicles, however, the seriousness of the vibration annoyance has not been considered so much. In this paper, a finite element model was built which was good for the low-frequency system(of fork-lift truck), and a forced vibration analysis was obtained for the component of 2n of harmonic orders from engine excitation to this model. Finally, a design optimization upon dynamic responses was made to minimize the vibration acceleration level at selected points representing the vibration level of the whole system.

• Structural Engineering and Mechanics
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• 제10권5호
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• pp.427-440
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• 2000

The formulas for the perturbation analysis with modes of close eigenvalues are derived in this paper. Emphasis is made on the consistency of the straightforward perturbation process, given the complete terms of perturbations in the zeroth-order, which is a form of Rayleigh quotient, and in the higher-orders. By dividing the perturbation of eigenvector into two parts, the first-order perturbation with respect to the modes of close eigenvalues is moved into the zeroth-order perturbation. The normality condition is employed to compute the higher-order perturbations of eigenvector. The algorithm can be condensed to a single mode with a distinct eigenvalue, and this can accelerate the convergence of the perturbation analysis. The example confirms that the perturbation approximation obtained from the suggested procedure is in a good accuracy on the eigenvalues, eigenvectors, and normality.

• 영어어문교육
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• 제15권2호
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• pp.121-150
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• 2009

This paper deals with contrastive analysis and interlanguage with respect to adjective ordering. It aimed to investigate how similar and different the orders of descriptive adjectives are in English and Korean, and how Korean EFL learners perceive the sequences of English descriptive adjectives. Data were collected from native English speakers and native Korean speakers and Korean EFL learners. The contrastive analysis showed that the order of English adjectives was size, opinion, condition, age, color, shape, material, and origin, whereas the Korean order was condition, age, opinion, color, size, shape, material, and origin. The relative order of the interlanguage was shown to be age, size, opinion, shape, condition, color, origin, and material, with the exceptions of the order of condition preceding age and that of size being the same position as condition. The interlanguage data manifested different aspects of ordering when compared with English and Korean: Some adjective combinations were similar to both English and Korean; Some were different from English or Korean; Some were different from both English and Korean. These ordering patterns are discussed in terms of such principles as the nouniness principle, the subjectivity/objectivity principle, the iconic principle, etc. On the basis of these results, some helpful suggestions are made.

• 한국건설관리학회논문집
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• 제17권2호
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• pp.39-48
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• 2016

최근 10년간 국내 해외건설사업 수주금액 현황은 지역별로는 중동지역과 공종별로는 산업설비(플랜트)가 전체 사업의 54.05%와 68.09%를 각각 차지하고 있는 실정이다. 중동지역 내 국가별 국내 해외건설사업의 비중은 2014년 기준으로 사우디아라비아가 34.1%로 가장 많은 부분을 차지하고 있는 상황이며, 공종별로는 산업설비(플랜트)가 56%로 가장 많은 비중을 차지하고 있다. 국내 해외건설사업은 최근 유가하락 등의 직 간접적인 영향이 중동지역의 산업설비(플랜트) 수주 감소로 이어져 어려움을 겪고 있다. 이러한 시점에서 경제변동에 따른 국내 해외건설사업의 수주규모 유지 및 공종 다변화를 위한 고찰이 필요할 것으로 판단된다. 이에 본 연구는 사우디아라비아를 대상으로 진출국가 경제변동이 공종별 국내 해외건설사업 수주실적에 미치는 영향을 실증분석하였다. 분석결과 대부분의 공종이 GDP와 투자기금의 영향이 높았고, 건축, 토목공종이 산업설비(플랜트)의 대체관계임을 확인할 수 있었다. 이는 국내 해외건설사업 수주실적 유지 및 공종다변화를 위한 기초자료로 활용 될 것으로 기대된다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.19-19
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• 2015

The term of Mushrooms means to spread like the April showers. After 18th century, the mycelium and spores of mushrooms were observed by microscope and then was denominated as fungi. About one hundred thousand species of mushrooms in appearance were worldly reported, and in Korea about four thousand species of mushrooms are estimated. In Korea, total of one thousand nine hundred one species of mushrooms have been recorded. Mushrooms belonging to the group of organisms called fungi, which must obtain their food from living plants or animals or from their remains after death. A large number of mushrooms grow in association with the roots of trees and other woody plants, called mycorrhizal fungi, both mushrooms and plants require this relationship for growth and development. And also many Mushrooms are saprobic, living on decayed various fallen leaves, twigs, trees and vegetable remains and etc. some of these million of spores settles on the proper habitat, these spores germinates and grows into a mass of threads, then a mycelium. This is the vegetable part of the mushrooms, what we call mushrooms are the carpophores, all the characteristics of the morphological features are appropriately used to identify species of mushrooms. Recently, identification and classification of mushrooms are newly confirmed by molecular analysis. In 2013, One thousand nine hundred one species of mushrooms in "List of Mushrooms in Korea" which published by the Korean Society of Mycology were recorded. Total of 238species, 107genera, 40families, 13orders, 6Classes belong to phylum Ascomycota. Total of 1,663species, 403genera 81families, 18orders, 7classes belong to phylum Basidiomycota.